1. Field
The following description relates generally to wireless communications, and more particularly to facilitating inter-frequency timing acquisition for neighboring cells of a wireless network.
2. Background
Wireless communication systems are widely deployed to provide various types of communication content, such as voice content, data content, and so on. Typical wireless communication systems can be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems can include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), or multi-carrier wireless specifications such as evolution data optimized (EV-DO), one or more revisions thereof, etc.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple mobile devices. Each mobile device can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. Further, communications between mobile devices and base stations can be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth.
For wireless communication in general, and particularly wireless systems employing a time division duplex (TDD) multiplexing technology, signal timing is an important aspect of successful transmission and reception of data. Wireless signals are generally divided in time into multiple time frames, comprising multiple time subframes. In TDD, time frames can be designated for uplink (UL) transmission or downlink (DL) transmission. This provides an overt mechanism for turn-based wireless transmission and reception to mitigate interference. Furthermore, accurate timing is an important part of successfully demapping and demodulating a wireless signal; without knowing what symbols to expect at a particular time, proper wireless reception can be difficult or impossible, depending on circumstances.
In a typical wireless mechanism, a wireless receiver can analyze received pilot signals of wireless base stations to establish a baseline signal timing configuration, among other things. This signal timing configuration can comprise, for instance, duration of signal frames and subframes, and start and stop times thereof. This measurement can be processor intensive, however, particularly when in range of a number of transmitters and where receiving a number of pilot signals. Particularly for mobile devices, unconnected to permanent source of electrical power, minimizing processing overhead and power consumption is a persistent goal, to extend battery life.
Upon entering a new network, a wireless receiver typically must perform timing analysis of at least one base station or network access point to initiate control communications therewith. Some exceptions may exist (e.g., where the terminal is in a known location and is preconfigured with a timing configuration for base stations within that location), but for cellular networks and many other wireless networks, this is a common procedure. Once initial timing and acquisition is achieved with one base station (e.g., a serving base station), the access terminal can continue to employ the timing configuration for communication with the serving base station as well as neighboring base stations utilizing the same timing configuration. However, where different timing configurations are employed among neighboring base stations, further processing may be required to hand off to, or otherwise decode signals of the neighboring base stations. Particularly when mobile (e.g., driving in a car), moving from one network cell to another can add significant processing overheard as network timing is acquired from one cell to another.